The most important election of our lifetimes is no longer in the hands of the candidates. Barring the capture of bin Laden, or Kerry hitting a grand slam in the World Series, neither candidate can shift the electorate. Each campaign spins its own story for every news event, letting voters believe whichever reconfirms their biases. Unless God declares Bush to be Satan (in which case he would still win Wyoming and Idaho), the polls won’t change.

So, who controls who wins? The answer is, surprisingly, America’s college students.

Without them — without us — Bush would likely win. In most electoral-college tallies, he dominates. National polls show a close race, but Bush has small leads in the swing states. Yet there is an important footnote to all poll results. Polls don’t simply report the preferences of 1,000 random people. Poll data are weighted to reflect how pollsters believe the electorate will turn out. Gallup guesses 39 percent Republican, 33 percent Democrat; Zogby estimates 39 percent Democrat, 33 percent Republican. No one knows for sure, and obviously, the actual turnout determines the winner.

Because this election will be determined by which side can get more voters to the polls, it’s all about volunteers. The election is now in the our hands, those of the 18- to 25-year-olds — the only people who have the free time, energy and inclination to make the calls, write the letters and ring the doorbells.

It almost shouldn’t be necessary. Political discontent is ready to erupt. Most Americans think the country is headed in the wrong direction. Moderates are breaking for Kerry by a 12-point margin. If Bush is re-elected, a staggering 91 percent of people want his second term to be different than his first. Both sides’ supporters equally like their respective candidate’s policies, but fully half of Kerry’s supporters are very angry with Bush.

Things shouldn’t be looking good for the GOP, so how can Bush be set to win? Two factors outweigh all others. First, the GOP has made its get-out-the-vote effort the best it has ever been, outstripping Democratic efforts. One-third of voters in swing states have been contacted by Bush’s campaign, while only one-fifth have heard from Kerry’s.

Second, Bush and his campaign strategist, Karl Rove, are among the best negative campaigners in American politics. Smear campaigns are designed to suppress voter turnout by destroying enthusiasm among a candidate’s supporters. Rove has executed the most devastating character assassination campaigns in modern history. His twist on negative campaigns is twisted: Forget weaknesses, and go after a candidate’s most unassailable strength. For example, in one campaign, Rove insinuated that the founder of the Children’s Trust Fund was a pedophile, and in the 2000 Republican primary, he suggested that Sen. John McCain’s years as a POW made him mentally unstable. In this election, the medals John Kerry earned for his sterling Vietnam service have been tarnished, and Kerry’s surprisingly consistent position on Iraq has formed the cornerstone of the charge of inconsistency.

And the smear won’t stop, as others join in: The conservative executives of the Sinclair Broadcast Group, which owns numerous TV stations and reaches nearly 25 percent of American homes, have ordered its stations, mostly in swing states, to preempt regular network programming immediately before the election to air a “documentary” smearing John Kerry’s war record.

The strong Republican get-out-the-vote effort plus the successful anti-Kerry smear campaign means that Kerry cannot win alone. If your convictions only result in a feisty pull of the lever or in an emphatic punch of the chad, then Bush wins. Kerry will likely lose unless our generation starts putting in time to make sure he wins. Plenty of grass-roots organizations are ready to fight, but they need volunteers. If you can’t get to a swing state, you can phone-bank or write letters. ACT (http://actforvictory.org/) has particular events for Connecticut residents. You can also volunteer through MoveOnPAC.org or, naturally, the Kerry campaign (http://volunteer.johnkerry.com/).

A Kerry victory on the backs of the grass-roots activism would be historic, and it is within reach. What Howard Dean started, Kerry can complete. A sea change will have occurred: Instead of campaigns barraging a passive electorate to curry its favor, this electorate will have risen up to carry its candidate to victory. It’s a subtle difference, but appreciable, especially because a Kerry victory virtually depends on it. In this election, voting is not enough. Treating this election like a sporting event is not enough. We are going to have to be, for once, American citizens of the sort sixth-grade civics teachers only dream about.

For the next 20-odd days, the election is in our hands. We are going have to act as if, well, as if we lived in a democracy. After all, we won’t want to say “I could have done something” on Nov. 3 — and every day for the next four years.

Paul Kalanithi is a second-year student at the School of Medicine.